Loss of either homologue in Drosophila (designated as Pink1 and parkin, respectively) results in strikingly similar phenotypes of severe mitochondrial dysfunction and degeneration of the indirect flight muscles, as well as the degeneration of a subset of dopaminergic neurons, thus mimicking a key hallmark of PD (Greene et al, 2003; Whitworth et al, 2005; Clark et al, 2006; Park et al, 2006). The gene discussed is PRKN; the disease is Parkinson disease.